Allegro’s A6217 integrates a high-side N-channel DMOS switch for DC/DC step-down (buck) conversion. A true average current is output using a cycle-by-cycle, controlled on-time method. This LED driver is targeted at the automotive lighting market and includes the following key applications: daytime running lights, front and rear fog lights, turn/stop lights, map lights, and dimmable interior lights.
Output current is user-selectable by an external current sense resistor. Output voltage is automatically adjusted to drive various numbers of LEDs in a single string, ensuring optimal system efficiency. LED dimming can be accomplished by logic-level or ‘chopped battery’ PWM, as well as analogue dimming capability. The A6217 also features switching frequency dithering for reduced EMI signature.
The A6217 is an enhanced version of the popular A6213 and is available in a pinout-equivalent eSOIC-8 package (LJ), or a more compact 3x3mm wettable flank DFN-10 (EJ). Both packages have an exposed pad for enhanced thermal dissipation, and are lead (Pb) free with 100% matt-tin leadframe plating.